Watlow Series 988LF - Manual (Page 3)

WATLOW Series 988LF User’s Manual i Introduction
Introduction To The Watlow
Series 988LF Controllers
Figure Int.1 -
The Series 988LF
Features.
Welcome to the Watlow Series 988LF, a dual output, single input, micro-
processor-based, 1/8 DIN, auto-tuning temperature control, featuring
automatic/manual capability with bumpless transfer. In the Auto mode,
the control has closed loop control with sensory feedback, while the
Manual mode has open loop control with user defined output power level.
The 988LF accepts a wide range of thermocouple sensors, along with RTD,
and process inputs. The primary output is Heating or Cooling, while the
secondary output can be Heating, Cooling, or Alarm.
With the Series 988LF, you can select either PID or ON/OFF for output 1
or Output 2. You may input a complete set of PID parameters for both
outputs, or select automatic tuning for both heat and cool from the front
panel. This includes proportional band, reset, rate, and cycle time. By
setting either output’s proportional band to zero, the Series 988LF
becomes a simple ON/OFF control with a 3°F or 1.7°C switching differen-
tial, 0.3°F or 0.17°C for 0.1° RTD.
Operator-friendly features include automatic LED indicators to aid in
monitoring and setup, as well as a calibration offset at the front panel.
The Watlow Series 988LF automatically stores all information in a non-
volatile memory.
TL W WA
PROCESS
L1 L2
DEV
% OUT
DISPLAY
SERIES 988LF
MODE
AUTO
MAN
Output 1
Control
Heat/Cool
Output 2
Control
Heat/Cool
Alarm
Input 1
Sensor Input
Input 2
Remote Set
Point Option
Auto-Tune
Heat/Cool
Process Deviation
from Set Point
Percent Power